package cn.edu.sdjzu.xg.bysj.controller.basic;

import cn.edu.sdjzu.xg.bysj.domain.ProfTitle;
import cn.edu.sdjzu.xg.bysj.service.ProfTitleService;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.alibaba.fastjson.serializer.SerializerFeature;
import lombok.extern.slf4j.Slf4j;
import util.Condition;
import util.ControllerHelper;
import util.JSONUtil;
import util.Pagination;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.sql.SQLException;
import java.util.Collection;
import java.util.List;

/**
 * 将所有方法组织在一个Controller(Servlet)中
 */
@Slf4j
@WebServlet("/profTitle.ctl")
public class ProfTitleController extends HttpServlet {

    /**
     * POST, http://localhost:8080/profTitle.ctl, 增加职称
     * 增加一个职称对象：将来自前端请求的JSON对象，增加到数据库表中
     *
     * @param request  请求对象
     * @param response 响应对象
     * @throws ServletException
     * @throws IOException
     */
    @Override
    protected void doGet(HttpServletRequest request,
                         HttpServletResponse response)
            throws ServletException, IOException {
        //创建JSON对象respMessage_jsonObj，以便往前端响应信息
        JSONObject respMessage_jsonObj = new JSONObject();

        //设置响应字符编码为UTF-8
        response.setContentType("application/json;charset=UTF-8");
        //将request body转换为JSON字串
        String req_jsonStr = JSONUtil.getJSON(request);
        //将request body解析为JSONObject对象
        JSONObject req_jsonObj = JSON.parseObject(req_jsonStr);
        //如果请求body为空
        if (req_jsonObj == null) {
            respMessage_jsonObj.put("message","未收到请求信息！");
            response.getWriter().println(respMessage_jsonObj);
            return;
        }
        //从JSONObject对象中读取键“id”的值（Java Object对象），req_jsonObj可能是{"id":1}
        Object id_obj = req_jsonObj.get("id");
        try {
            //如果id_Obj != null, 说明请求数据有id键，是请求某个对象
            if (id_obj != null) {
                int id_int = Integer.parseInt(id_obj.toString());
                responseProfTitle(id_int, response);
            } else {//请求中包含条件和分页信息，需要响应多个对象
                //读取分页信息，形成分页对象
                //从JSONObject对象中读取 “pagination” 键对应的值(JSONObject对象)
                Pagination pagination = ControllerHelper.getPagination(req_jsonObj);
                //从请求JSONObject对象中读取键“conditionList”对应的值(描述查询条件的JSONArray对象)
                List<Condition> conditionList = ControllerHelper.getConditions(req_jsonObj);
                //响应多个信息，其中conditionList, pagination两个对象引用为空是可能的
                this.responseProfTitles(response, conditionList, pagination);
            }
        } catch (SQLException e) {
            respMessage_jsonObj.put("message", "数据库操作异常");

            //响应respMessage_jsonObj到前端
            response.getWriter().println(respMessage_jsonObj);
            //打印异常栈，方便调试（要用log4j代替）
            log.error(e.getMessage());
        } catch (Exception e) {
            respMessage_jsonObj.put("message", "网络异常");
            //响应respMessage_jsonObj到前端
            response.getWriter().println(respMessage_jsonObj);
            //打印异常栈，方便调试（要用log4j代替）
            log.error(e.getMessage());
        }
    }

    //按分页信息响应符合条件的对象和对象总数
    private void responseProfTitles(HttpServletResponse response,
                                 List<Condition> conditionList,
                                 Pagination pagination)
            throws ServletException, IOException, SQLException {
        //分页获得满足条件的所有对象
        Collection<ProfTitle> profTitles= ProfTitleService.getInstance()
                .findAll(conditionList, pagination);
        //第二个参数可以防止循环引用
        String profTitles_jsonStr = JSON.toJSONString(profTitles,
                SerializerFeature.DisableCircularReferenceDetect);
        //创建JSON对象resp_jsonObj，以便往前端响应综合信息
        JSONObject resp_jsonObj = new JSONObject();
        resp_jsonObj.put("totalNum", pagination.getTotalNum());
        resp_jsonObj.put("data", profTitles_jsonStr);
        //响应resp_jsonObj到前端0
        response.getWriter().println(resp_jsonObj);
    }

    //响应一个对象
    private void responseProfTitle(int id, HttpServletResponse response)
            throws ServletException, IOException, SQLException {
        //根据id查找
        ProfTitle profTitle = ProfTitleService.getInstance().find(id);
        String profTitle_jsonStr = JSON.toJSONString(profTitle);
        //响应profTitle_jsonStr到前端
        response.getWriter().println(profTitle_jsonStr);
    }

    /**
     * POST, http://localhost:8080/profTitle.ctl, 增加职称
     * 增加一个职称对象：将来自前端请求的JSON对象，增加到数据库表中
     * @param request 请求对象
     * @param response 响应对象
     * @throws ServletException
     * @throws IOException
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        //设置请求字符编码为UTF-8
        request.setCharacterEncoding("UTF-8");
        String profTitle_json = JSONUtil.getJSON(request);
        //将JSON字串解析为对象
        ProfTitle profTitleToAdd = JSON.parseObject(profTitle_json, ProfTitle.class);
        //设置响应字符编码为UTF-8
        response.setContentType("application/json;charset=UTF-8");
        //创建JSON对象message，以便往前端响应信息
        JSONObject message = new JSONObject();
        //在数据库表中增加对象
        try {
            ProfTitleService.getInstance().add(profTitleToAdd);
            message.put("message", "增加成功");
            log.error("增加成功");
        }catch (SQLException e){
            message.put("message", "数据库操作异常");
            log.error(e.getMessage());
        }catch(Exception e){
            message.put("message", "网络异常");
            log.error(e.getMessage());
        }
        //响应message到前端
        response.getWriter().println(message);
    }
    /**
     * DELETE, http://localhost:8080/profTitle.ctl?id=2, 删除id=2的职称
     * 删除一个职称对象：根据来自前端请求的id，删除数据库表中id的对应记录
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    @Override
    protected void doDelete(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        //将request参数转换为JSON字串
        String request_json_str = JSONUtil.getJSON(request);
        //将请求body解析为要删除的Teacher的id对应的JSONObject对象(可能是{"id":1})
        JSONObject idOfTeacherToDelete_jsonObj = JSON.parseObject(request_json_str);
        //从JSONObject对象中读取键“id”的值（Java Object对象），
        Object id_obj = idOfTeacherToDelete_jsonObj.get("id");
        int id_int = Integer.parseInt(id_obj.toString());
        //设置响应字符编码为UTF-8
        response.setContentType("application/json;charset=UTF-8");
        //创建JSON对象respMessage_jsonObj，以便往前端响应信息
        JSONObject respMessage_jsonObj = new JSONObject();
        try {
            //到数据库表中删除对应的教师
            ProfTitleService.getInstance().delete(id_int);
            respMessage_jsonObj.put("message", "删除成功");
            log.error("删除成功");
        } catch (SQLException e) {
            respMessage_jsonObj.put("message", "数据库操作异常");
            //打印异常栈，方便调试（要用log4j代替）
            log.error(e.getMessage());
        } catch (Exception e) {
            respMessage_jsonObj.put("message", "网络异常");
            //打印异常栈，方便调试（要用log4j代替）
            log.error(e.getMessage());
        }
        //响应respMessage_jsonObj到前端
        response.getWriter().println(respMessage_jsonObj);
    }
    /**
     * PUT, http://localhost:8080/profTitle.ctl, 修改职称
     *
     * 修改一个职称对象：将来自前端请求的JSON对象，更新数据库表中相同id的记录
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    @Override
    protected void doPut(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        //设置请求字符编码为UTF-8
        request.setCharacterEncoding("UTF-8");
        String profTitle_json= JSONUtil.getJSON(request);
        //将JSON字串解析为对象
        ProfTitle rofTitleToUpdate = JSON.parseObject(profTitle_json, ProfTitle.class);

        //设置响应字符编码为UTF-8
        response.setContentType("application/json;charset=UTF-8");
        //创建JSON对象message，以便往前端响应信息
        JSONObject message = new JSONObject();
        //到数据库表修改对象对应的记录
        try {
            ProfTitleService.getInstance().update(rofTitleToUpdate);
            message.put("message", "修改成功");
            log.error("修改成功");
        }catch (SQLException e){
            message.put("message", "数据库操作异常");
            log.error(e.getMessage());
        }catch(Exception e){
            message.put("message", "网络异常");
            log.error(e.getMessage());
        }
        //响应message到前端
        response.getWriter().println(message);
    }
}

